What is the tower used for and what have they charged you with? A little more info might help people to help you.
Simply explaining that the phantom and the tower can not talk (interfere) with each other because they are separated by a massive difference in frequency may help. You have a separation in gigahertz. The difference is so massive that it's not like a Chinese person trying to talk to a Portuguese person, it's like a Chinese person trying to talk to a rock - that lives on the moon. There's no chance of interference at these frequencies, unless you're missing something and they also have 2.4ghz or 5.8ghz (if it's a phantom 4) on the tower - then they'd be correct and they'd for sure be picking you up if you're within line of sight.
Make sure they know what they're talking about first, then maybe try to explain that antennas are specifically tuned for a very tight range of frequencies and that there is no way that the two devices can interact.
Simply explaining that the phantom and the tower can not talk (interfere) with each other because they are separated by a massive difference in frequency may help. You have a separation in gigahertz. The difference is so massive that it's not like a Chinese person trying to talk to a Portuguese person, it's like a Chinese person trying to talk to a rock - that lives on the moon. There's no chance of interference at these frequencies, unless you're missing something and they also have 2.4ghz or 5.8ghz (if it's a phantom 4) on the tower - then they'd be correct and they'd for sure be picking you up if you're within line of sight.
Make sure they know what they're talking about first, then maybe try to explain that antennas are specifically tuned for a very tight range of frequencies and that there is no way that the two devices can interact.